Biology

Font size:
Medium Text Large Text

Print this page:Print this page


Whitworth Home Page > Biology >

Personal Page: Frank Caccavo


Education

  • B.S. Marine Biology, Southampton College, 1989
  • M.S. Microbiology, University of New Hampshire, 1992
  • Ph.D. Microbiology, University of Oklahoma, 1995

Teaching Responsibilities:

  • Infectious Disease (BI 196) (Fall)
  • Introduction to Biochemistry (Fall)
  • Advanced Microbiology (BI 347) (Fall)
  • Medical Microbiology (BI 204) (Spring)

Research Interests:

Dissimilatory metal-reducing bacteria (DMRB) gain energy to support anaerobic growth by coupling the oxidation of hydrogen, organic acids, aromatic hydrocarbons, or long-chain fatty acids to the reduction of a variety of metals, including iron, manganese, cobalt, uranium, technetium, arsenic, selenium and chromium. The metabolism of DMRB significantly influences the geochemistry and ecology of anaerobic sediments, and can simultaneously lead to the immobilization, detoxification, or precipitation of reduced metal species. Microbial metal reduction is therefore significant from economic, ecological, and public health perspectives. The factors controlling the rate and extent of metal reduction, and thus the extent of organic matter mineralization, in natural marine, estuarine and freshwater environments are not well understood. The focus of my current and future research is to gain a better understanding of the ecology, biochemistry, and physiology of these bacteria with the ultimate purpose of applying this metabolism in bioremedial and industrial technologies.

Current Research Projects:

  • Interactions between DMRB and ferric iron minerals. I am interested in how DMRB interact with insoluble Fe(III) minerals and use them as a sole source of energy at the molecular level. This information is needed to predict the rate and extent of Fe(III) reduction and organic matter oxidation, and the survival and transport of these organisms in Fe(III)-reducing environments. We are studying the mechanisms by which DMRB adhere to and colonize Fe(III) bearing minerals. We are also studying cell-surface proteins that chelate ferric iron from those minerals. This work is funded through the Soils and Soil Biology Program at the U.S. Department of Agriculture. Senior biology student Scott Sulpizio is currently working on this project for the summer 2001.
  • DMRB as agents of Bioremediation. Ultramicrobacteria (UMB) are greatly reduced in size (ca 0.3 mm), non-adherent, and readily penetrate porous media. Because UMB retain all of their genotypic characteristics, they are ideally suited for the delivery of biodegradative capability for in situ bioremediation. We are examining the potential for using UMB of dissimilatory metal-reducing bacteria as a means of in situ remediation of heavy metal- and halogenated hydrocarbon-contaminated groundwater. This work is being performed in collaboration with scientists at Montana State University and is currently funded through the M.J. Murdock Charitable Trust College Research Program for Life Sciences. Senior biology student Kathleen Fisher is currently working on this project for the summer 2001.

    * Students interested in participating in this research should contact Dr. Caccavo.

Recent Publications:

  • Cummings, D.E., F. Caccavo, Jr., S. Fendorff, and R.F. Rosenzweig. 1999. Arsenic mobilization by the dissimlatory Fe(III)-reducing bacterium Shewanella alga BrY. Environ. Sci. Technol. 33:723-729.
  • Caccavo, Jr., F. Protein-mediated adhesion of the dissimilatory Fe(III)-reducing bacterium Shewanella alga BrY to hydrous ferric oxide. Appl. Environ. Microbiol. 65:5017-5022.
  • Cummings, D.E., A.W. March, B. Bostick, S. Spring, F. Caccavo, Jr., S. Fendorf and R.F. Rosenzweig. 2000. Evidence for microbial Fe(III) reduction in anoxic, mining-impacted lake sediments (Lake Coeur d'Alene, USA). Appl. Environ. Microbiol. 65:5017.
  • Das, A. and F. Caccavo, Jr. 2000. Dissimilatory Fe(III) oxide reduction by Shewanella alga BrY requires adhesion. Curr. Microbiol. 40:344-347.
  • Das, A. and F. Caccavo, Jr. 2001. Adhesion of the dissimilatory Fe(III)-reducing bacterium Shewanella alga BrY to crystalline Fe(III) oxides. Curr. Microbiol. 42:151-154.

Recent Presentations:

  • Caccavo, Jr., F. Protein-mediated adhesion of the dissimilatory Fe(III)-reducing bacterium Shewanella alga BrY to hydrous ferric oxide. Abstr. 99th Meet. Am. Soc. Microbiol. 1999.
  • Caccavo, Jr., F. Bacterial Iron Mineral Respiration: A natural strategy for enhanced bioavailability. Abstr. 4th Int. Symp. on Subsurface Microbiol., 1999.
  • Cummings, D, F. Caccavo, Jr., A. March, S. Spring, B. Bostick, S. Fendorf and F. Rosenzweig. Evidence for and significance of microbial Fe(III) reduction in mine tailings-enriched anoxic lake sediments. Abstr. 4th Int. Symp on Subsurface Microbiol., 1999.
  • Gerlach, R, A. Cunningham and F. Caccavo, Jr. Chromium elimination with microbially reduced iron: redox-reactive biobarriers. Abstr. 5th Int. Symp. In situ and on-site bioremediation, 1999.
  • Gerlach, R.A., F. Caccavo, Jr., and A.B. Cunningham. Chromium(VI)-Elimination from contaminated Groundwaters Using Redox-Reactive Biobarriers. Poster Presentation at 1999 Conference on Hazardous Waste Research - Gateways to Environmental Solutions. Great Plains/Rocky Mountain Hazardous Substance Research Center. St. Louis, MO, May 24-27, 1999. (Honorable Mention in Best Poster Contest)